Abstract:

Objective
 To explore the possibility of differentiation of canine bone marrow-derived mesenchymal stem cells(BMSCs) into smooth muscle cells(SMCs) and the potential of using these SMCs as cell sources for engineering of blood vessel construction.
Methods  Canine BMSCs were isolated by density gradient centrifugation and cultivated in DMEM supplemented with PDGF-BB and vitamin C(VIT-C).The phenotypic characteristics of  BMSCs were identified by morphological observation,α-SMA and SMMHC in SMCs at passage 4-6 were analyzed by  immunofluorescent staining,and the positive rates of SMCs at passage 5,6 were detected by flow cytometry.
Results The BMSCs cultivated in the conditioned medium for SMCs showed SMC-like morphology:they displayed spindle-shape in morphology and were  positive for α-SMA but negative for SMMHC.42 d and 33 d were needed to obtain 10⁷-10⁸ seeding cells without or with PDGF-BB/VIT-C in culture medium respectively.With the subculture,the percentage of α-SMA positive cells increased from 57.8% at passage 5 to 66.8% at passage 6,suggesting under aforementioned cultured conditions,more BMSCs turned into SMCs.Conclusion BMSCs can be differentiated into SMCs under appropriate culture conditions,suggesting the potentiality of using these SMCs as cell sources for tissue engineering of blood vessel construction.

Key words: bone marrow-derived mesenchymal stem cells;smooth muscle cells;tissue engineering;growth factor